What it is
C12-15 alkyl benzoate is an ester (CAS 68411-27-8) formed by combining benzoic acid with a mix of fatty alcohols 12 to 15 carbons long. It is an often-used emollient prized for its light, silky, fast-spreading feel and for being mild on skin and eyes. In sunscreens it is especially useful because it is a good solvent for the oil-soluble UV filters, helping dissolve and distribute them evenly, and it can also lend mild antimicrobial support to a formula.
Safety & warnings
C12-15 alkyl benzoate is regarded as very mild to both skin and eyes, spreads easily, and is generally suitable for sensitive-skin formulas. It is not a notable common allergen, and its main appeal is a clean, light skin feel that makes heavy UV-filter blends more wearable. Anyone who reacts to a specific finished sunscreen should patch test, as reactions in such products usually involve other ingredients.
Origin & sourcing
It is produced synthetically by esterifying benzoic acid, which itself occurs naturally in many berries and resins, with a blend of C12-15 fatty alcohols. The fatty-alcohol portion is commonly sourced from plant oils, giving a refined, consistent emollient.
Questions everyone asks
What does C12-15 alkyl benzoate do in sunscreen?
It is a light emollient and a strong solvent for oil-soluble UV filters, so it dissolves and spreads the filters while giving a silky, non-greasy finish.
Is it gentle on skin?
It is considered very mild to both skin and the eye area and is commonly used in formulas for sensitive skin.
Is it natural?
It is synthesized from benzoic acid, which occurs naturally in berries and resins, combined with fatty alcohols, so it is a refined synthetic ester from partly natural building blocks.